w32: Add comment about a compiler warning

--

src/assuan-support.c

@@ -238,6 +238,12 @@ my_connect (assuan_context_t ctx, int sock, struct sockaddr *addr,
 }
 
 
+/* Note for Windows: Ignore the incompatible pointer type warning for
+   my_read and my_write.  Mingw has been changed to use int for
+   ssize_t on 32 bit systems while we use long.  For 64 bit we use
+   int64_t while mingw uses __int64_t.  It doe not matter at all
+   because under Windows long and int are both 32 bit even on 64
+   bit.  */
 struct assuan_system_hooks _gpgme_assuan_system_hooks =
   {
     ASSUAN_SYSTEM_HOOKS_VERSION,